1. Field of the Invention
The present invention relates to a printing apparatus for printing by transferring liquid to a print medium.
2. Description of the Related Art
Printing apparatuses adapted to print a print medium such as a sheet of paper, which have been hitherto known, include, for example, inkjet heads adapted to eject ink onto a sheet of paper or the like. There have been various types of the inkjet heads. For instance, one such inkjet head includes a passage unit that has plural individual ink passages including pressure chambers each communicated with a nozzle, and also includes plural piezoelectric actuator units each adapted to apply pressure to ink in each of the corresponding pressure chambers (see, for example, JP-A-2004-160967 (FIG. 1)). Incidentally, each of the piezoelectric actuator units has plural individual electrodes respectively corresponding to the plural pressure chambers, and also has common electrodes respectively facing the plural individual electrodes, piezoelectric layers, each of which is sandwiched between the corresponding individual electrode and the corresponding common electrode and is made of lead zirconate titanate (PZT). Further, when a drive voltage is supplied to a predetermined one of the individual electrodes, an electric field acts upon the piezoelectric layer sandwiched between the predetermined individual electrode and the corresponding common electrode, so that the piezoelectric layer is partly deformed. With this deformation of the piezoelectric layer, pressure is applied to ink in the corresponding pressure chamber. Thus, ink is ejected from the nozzle communicated with this pressure chamber.